Fluorescent lamps are known electric discharge sources in which light is predominantly produced by fluorescent powders activated by ultraviolet energy generated by a mercury arc. The lamps, usually in the form of a long tubular bulb with an electrode sealed into each end, contain mercury vapor at low pressure with a small amount of inert gas, principally argon, for starting. The inner walls of the bulb are coated with light emitting phosphors. When the proper voltage is applied an arc is produced by current flowing between the electrodes through the mercury vapor. The discharge generates some visible radiation, or light, but mostly invisible ultraviolet radiation. The ultraviolet in turn excites the phosphors to emit light.
While fluorescent lamps have long been known for their high luminous efficacy (i.e., their light output is high relative to the power consumed) their use as home lighting sources has been overshadowed by the relatively inefficient incandescent bulb. Primarily, this situation has arisen because of the inconvenient shape and size of the typical fluorescent bulb (long, tubular, and awkward to handle) and the fact that auxiliary circuitry, such as starting systems and ballast, are necessary for their operation.
In these days of soaring energy costs it would be an advance in the art to provide a fluorescent light source that is compact in design, easy to use and replace and compatible with incandescent fixtures.